This invention relates to an actuator for a wire matrix printer and to a method for securing a print wire to a plunger means used in the actuator.
The actuator of this invention may be used in a high speed wire matrix printer of the types shown in U.S. Pat. Nos 3,795,298, and 3,833,105, for example. The printers described therein are capable of forming characters by selectively impacting one or more of seven print wires (arranged in a vertical column near the associated platen) against an inking ribbon so as to print "dots" upon the surface of a record medium located behind the ribbon and held on the platen of the associated printer. A plurality of the columns printed are related so as to form any character or symbol, typically within a five by seven matrix or a seven by nine matrix.
Some other prior art actuators for wire matrix printers are shown in the following U.S. Pat. Nos.: 3,592,311, 3,729,079, 3,770,092, 3,787,791, 3,831,729, and 3,835,975.
None of the prior art references cited shows a plunger-type actuator for a wire matrix printer which utilizes a magnet means for biasing the plunger means to a first or a ready position against the bias of a spring means, and a neutralizing coil for neutralizing the holding effect of the magnet means enabling the plunger means to travel ballistically at least part way towards a second or impact position. Neither the specific construction of the spring means nor the specific method of attaching a print wire to the associated plunger means is shown in said references.